When melting materials in an injection molding system, uniform melting and temperature of the meltable material should be implemented and maintained in order to produce quality molded parts. Some injection molding machines use an induction coil to melt material before injecting the material into a mold. However, magnetic fluxes from the induction coil tend to cause molten materials to move unpredictably, which can make it difficult to control the uniformity and temperature of the molten material. Additionally, the molten material has to be retained in the melt zone so that it does not mix too much or cool too quickly. Utilizing effective vessels during melting can improve quality of parts formed from molten material.